<template>
<!-- v-for搭配data数组用 -->
  <div>
    <p>请选择你要购买的书籍</p>
    <ul>
      <li v-for="(item,ind) in arr" :key="ind">
      <!-- {{item["name"]}}相当于.name 都是拿到书名的属性值 -->
      <span>{{item["name"]}}</span>
      <button @click="buy(ind)">买书</button>
      </li>
    </ul>
    <table border="1" width="500" cellspacing="0">
      <tr>
        <th>序号</th>
        <th>书名</th>
        <th>单价</th>
        <th>数量</th>
        <th>合计</th>
      </tr>
      <tr v-for="(item,index) in arr" :key="index">
        <td>{{index + 1}}</td>
        <td>{{item["name"]}}</td>
        <td>{{item["price"]}}</td>
        <td>{{item["count"]}}</td>
        <td>{{item["price"]*item["count"]}}</td>
      </tr>
    </table>
    <p>总价格为:{{allprice}}} </p>
  </div>
</template>

<script>
export default {
  data () {
    return {
      arr: [
        {
          name: '水浒传',
          prce: '107',
          count: 0
        },
        {
          name: '西游记',
          prce: '192',
          count: 0
        },
        {
          name: '三国演义',
          prce: '219',
          count: 0
        },
        {
          name: '红楼梦',
          prce: '178',
          count: 0
        }
      ]
    }
  },
  // 买书 数量+1
  methods: {
    buy (index) {
      this.arr[index].count++
    }
  },
  computed: {
    allprice () {
      return this.arr.reduce((sum, obj) => {
        return (sum += obj.price * obj.count)
      }, 0)
    }
  }
}
</script>

<style scoped lang='less'>

</style>
